Notices
C4 Tech/Performance L98 Corvette and LT1 Corvette Technical Info, Internal Engine, External Engine

96 corvette stalls when hot

 
Old 07-06-2019, 02:53 PM
  #1  
Dave Witman
CF Senior Member
Thread Starter
 
Dave Witman's Avatar
 
Member Since: Oct 2004
Location: Middletown Delaware
Posts: 596
Likes: 0
Received 3 Likes on 3 Posts
Default 96 corvette stalls when hot

96 when hot surges and stalls at 2000 rpm. If you catch it before it stalls it will idle. After it stalls it will restart and not stall again entill next day when it goes thru the same cycle. I would like to read opti low res and high res signals. Can this be done on a scanner or do i need an oscilloscope. There are no codes, replaced icm, coil, optispark. map, tps. iac. fuel filter. cleaned throttle body. all four 02 sensors. new battery fuel pressure good and steady during failure.

Last edited by Dave Witman; 07-06-2019 at 02:59 PM.
Dave Witman is offline  
Old 07-07-2019, 10:19 AM
  #2  
Kevova
CF Senior Member
 
Kevova's Avatar
 
Member Since: Sep 2013
Location: near the thumb in the mitten
Posts: 4,104
Received 386 Likes on 370 Posts
Default

O scope required to watch Opti resolution pattern. Scanner with snap shot function catching event possibly could show what is dropping out. Alot of new parts all related to this condition?
Kevova is offline  
Old 07-08-2019, 04:58 PM
  #3  
Dave Witman
CF Senior Member
Thread Starter
 
Dave Witman's Avatar
 
Member Since: Oct 2004
Location: Middletown Delaware
Posts: 596
Likes: 0
Received 3 Likes on 3 Posts
Default

Ok little update got it to fail as usual but this time it was hard to start managed to get a noid light on and i have no injector pulses. Unfortunately problem cleared again before i could check for spark. I wish this would just fail so i could find the cause.
Dave Witman is offline  
Old 07-08-2019, 06:29 PM
  #4  
Kevova
CF Senior Member
 
Kevova's Avatar
 
Member Since: Sep 2013
Location: near the thumb in the mitten
Posts: 4,104
Received 386 Likes on 370 Posts
Default

Codes? Opti work different than HEI. Opti sends signal to PCM. PCM then sends signal to ICM for spark. PCM uses only Opti reference for injectors. Crank sensor is more for misfire ID protocol it's used with OBD2.
Kevova is offline  
Old 07-08-2019, 10:04 PM
  #5  
MatthewMiller
CF Senior Member
 
MatthewMiller's Avatar
 
Member Since: Aug 2015
Location: St. Charles MO
Posts: 2,324
Received 335 Likes on 286 Posts
Default

Yep, so the fact that injectors are getting no signal does tend to implicate the Opti. Is the tach signal cratering or going crazy when this happens? That's another sign.
MatthewMiller is offline  
Old 07-08-2019, 11:26 PM
  #6  
Dave Witman
CF Senior Member
Thread Starter
 
Dave Witman's Avatar
 
Member Since: Oct 2004
Location: Middletown Delaware
Posts: 596
Likes: 0
Received 3 Likes on 3 Posts
Default

No codes that would be to easy. Engine surged bad this time before stall so tach looked like it was following engine rpm.
Dave Witman is offline  
Old 07-09-2019, 01:58 AM
  #7  
MatthewMiller
CF Senior Member
 
MatthewMiller's Avatar
 
Member Since: Aug 2015
Location: St. Charles MO
Posts: 2,324
Received 335 Likes on 286 Posts
Default

Originally Posted by Dave Witman View Post
No codes that would be to easy. Engine surged bad this time before stall so tach looked like it was following engine rpm.
Then I would guess that it's not the opti, since the tach gets it's signal directly from the opti sensor. Did you put the noid light on both banks of injectors? The PCM has two amplifiers (I think that's what they're called?) for the injector signals - one for each bank. If side is firing and the other isn't during these failures, then maybe it's that part of the PCM.
MatthewMiller is offline  
Old 07-09-2019, 11:17 AM
  #8  
Kevova
CF Senior Member
 
Kevova's Avatar
 
Member Since: Sep 2013
Location: near the thumb in the mitten
Posts: 4,104
Received 386 Likes on 370 Posts
Default

Full size uses same PCM so used PCM programmed to your car could be reasonable. Collecting Mitsubishi Opti sensors off wrecks could also be worthwhile. Since you are shopping for PCM. When hard to start afterwards what did tach do? IDK I would want to experience hard start atleast one more time with a scanner, before guessing. If Opti just turns off sending no signals, engine just turns off no codes.
Kevova is offline  
Old 07-10-2019, 09:32 AM
  #9  
Dave Witman
CF Senior Member
Thread Starter
 
Dave Witman's Avatar
 
Member Since: Oct 2004
Location: Middletown Delaware
Posts: 596
Likes: 0
Received 3 Likes on 3 Posts
Default

Will have access to oscilloscope this weekend to better test signals from opti. Tach seems normal when cranking.
Dave Witman is offline  
Old 07-10-2019, 09:47 AM
  #10  
MatthewMiller
CF Senior Member
 
MatthewMiller's Avatar
 
Member Since: Aug 2015
Location: St. Charles MO
Posts: 2,324
Received 335 Likes on 286 Posts
Default

Originally Posted by Dave Witman View Post
Will have access to oscilloscope this weekend to better test signals from opti. Tach seems normal when cranking.
There is both a hi-res and low-res signal from the opti sensor. Check for both. However, if only the hi-res were out the car would continue to run, just not quite as well (but a lot better than sputtering and barely running or stalling frequently). If the low-res were out, I believe that would kill your tach signal. It's worth checking though.
MatthewMiller is offline  

Thread Tools
Search this Thread
Quick Reply: 96 corvette stalls when hot


Contact Us - About Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: